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thin film damping in frequency domain
Posted 11 mai 2017, 18:11 UTC−4 2 Replies
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Hi
I'm simulating squeeze damping on cantilever. I use solid mechanics model and study in frequency domain perturbation. I add thin film damping and harmonic perturbation boundary load for cantilever, but the result is not correct, the quality factor calculated from resonance peak is too high, (comparing with experiment result) and there isn't distribution pressure on surface when i plot. So how to add the condition correctly and what conditions am i missing.
I'm simulating squeeze damping on cantilever. I use solid mechanics model and study in frequency domain perturbation. I add thin film damping and harmonic perturbation boundary load for cantilever, but the result is not correct, the quality factor calculated from resonance peak is too high, (comparing with experiment result) and there isn't distribution pressure on surface when i plot. So how to add the condition correctly and what conditions am i missing.
2 Replies Last Post 11 mai 2017, 19:39 UTC−4
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Posted:
8 years ago
Updated:
8 years ago
(I assume you mean squeeze film damping)
The experiment is reality,* your simulation is subject to assumptions that may or may not be correct.
A long time ago I attempted to simulate the quality factor for a MEMS structure. The simulated Q was always somewhat higher than the measured value.
I never did resolve the issue- had other things to do- but if I needed to- I would look in the literature for analytic theory and other simulations to compare with mine. I would also consider whether there were other sources of damping that I had omitted.
* Of course, this assumes that the measurements were done correctly.
DW Greve
DWGreve Consulting
The experiment is reality,* your simulation is subject to assumptions that may or may not be correct.
A long time ago I attempted to simulate the quality factor for a MEMS structure. The simulated Q was always somewhat higher than the measured value.
I never did resolve the issue- had other things to do- but if I needed to- I would look in the literature for analytic theory and other simulations to compare with mine. I would also consider whether there were other sources of damping that I had omitted.
* Of course, this assumes that the measurements were done correctly.
DW Greve
DWGreve Consulting
Please login with a confirmed email address before reporting spam
Posted:
8 years ago
Thank you DW Greve
I compare simulation result with a result in a paper.
Quality factor is not slightly higher and there isn't pressure distribution on surface when i plot.
I also use time dependent domain with same conditions, the quality factor is good agreement with experiment (about 10%).
I compare simulation result with a result in a paper.
Quality factor is not slightly higher and there isn't pressure distribution on surface when i plot.
I also use time dependent domain with same conditions, the quality factor is good agreement with experiment (about 10%).